In the current phase of this randomized controlled trial, the principal objective is to determine ability to control blood pressure by nutritional-hygienic non-pharmacologic means in a sizeable proportion of hypertensive individuals (most of whom were originally characterized as "mild" hypertensives), normalized by pharmacologic treatment over 5 years in the national cooperative Hypertension Detection and Follow-Up Program (HDFP). The goal is, by modification particularly of overweight and excess sodium consumption in the intervention Group (Group I), to maintain satisfactory blood pressure levels using no antihypertensive medications. A second goal, for those not able to be controlled when all medications are withdrawn is--by means of diet modification--to achieve control using less medication (step or dosage), compared to entry regimen. A third objective is, in another randomly assigned group (Group II) to assess whether previous long-term blood pressure control by pharmacologic means makes it possible to discontinue or reduce drug treatment without nutritional-hygienic intervention. Both groups are being compared with their status before entering the trial, with each other at 6-month assessment points over two years of observation, and with a third group (Group III) maintained on drug treatment throughout the trial. Careful blood pressure monitoring and strict criteria regarding return to drugs where necessary are essential trial elements. At present, with major progress in reducing weight and sodium in Group I patients, the proportion requiring return to medication in order to remain normotensive is half that in Group II (no nutritional intervention). However, a critical question is whether this ability to control pressure by nutritional means can be maintained long-term. The aim of the proposed new phase of the study would permit intervention, treatment and observation for a total of 5 years (i.e. 3 years beyond the end of the current phase) to help answer this question.